In this paper, we propose a novel floorplanning algorithm based on simulated annealing on GPUs. Simulated annealing is an inherently sequential algorithm, far from the typical programs suitable for Single Instruction ...
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ISBN:
(纸本)9781612849133
In this paper, we propose a novel floorplanning algorithm based on simulated annealing on GPUs. Simulated annealing is an inherently sequential algorithm, far from the typical programs suitable for Single Instruction Multiple Data (SIMD) style concurrency in a GPU. We propose a fundamentally different approach of exploring the floorplan solution space, where we evaluate concurrent moves on a given floorplan. We illustrate several performance optimization techniques for this algorithm on GPUs. Compared to the sequential algorithm, our techniques achieve 6-160X speedup for a range of MCNC and GSRC benchmarks, while delivering comparable or better solution quality.
An approach using an experimentally built low-order model is proposed for the estimation of time-varying heat sources. In a first step, a low order dynamical system of equations, linking up temperatures at a set of sp...
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An approach using an experimentally built low-order model is proposed for the estimation of time-varying heat sources. In a first step, a low order dynamical system of equations, linking up temperatures at a set of specific points to heat sources strengths, is identified from experimental data using the Modal Identification Method. In a second step, the low order model is used to efficiently solve the transient inverse problem for the estimation of heat sources intensities from temperature measurements. The proposed approach is illustrated with an experimental set-up involving thermal diffusion with convective and radiative boundary conditions. (C) 2009 Elsevier Ltd. All rights reserved.
This study used the finite element method with linear least-squares error method to construct a simple non-iterative inverse operation procedure, for solving non-Fourier heat transfer effect in irregular geometry. Num...
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This study used the finite element method with linear least-squares error method to construct a simple non-iterative inverse operation procedure, for solving non-Fourier heat transfer effect in irregular geometry. Numerical validation indicated that, irregular geometry would enhance heat wave reflection and thus make temperature distribution more complex, moreover, non-Fourier heat transfer has limited heat wave propagation speed, heat information fails to be reflected in time at measure point of the other side, hence, inverse operation difficulty increases. However, sequential algorithm constructed by this study is able to estimate unknown boundary condition correctly and efficiently at every instant by only one array operation in successive time steps. In addition, by measuring a few future time temperatures, the sensitivity of estimated result to measurement error can be effectively reduced as well. (C) 2010 Elsevier Ltd. All rights reserved.
To broaden the application of inverse estimation, the purpose of this study is to estimate the unknown temperature boundary condition of the complex or irregular shape, like the high pressure gas tank. An inverse algo...
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To broaden the application of inverse estimation, the purpose of this study is to estimate the unknown temperature boundary condition of the complex or irregular shape, like the high pressure gas tank. An inverse algorithm based on the sequential method and the concept of future time combined with the finite-element method is proposed to solve the two dimensional irregular shape heat conduction problems. Special features about the proposed method are that the stiffness matrix of the irregular shape can be solved from the finite-element method and used by the inverse algorithm. The estimated results are quite accurate with the consideration of future time in the different measured errors, the various sensor's number and the sensor location. These results show that the proposed method is an accurate, sturdy, and efficient method for solving several realistic applications. (C) 2010 Elsevier Ltd. All rights reserved.
This study employed the finite element method and rearranged the matrix to establish an inverse operation without iteration, in order to simultaneously estimate the internal heat generation and root temperature of the...
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This study employed the finite element method and rearranged the matrix to establish an inverse operation without iteration, in order to simultaneously estimate the internal heat generation and root temperature of the T-shaped fin. The results of numerical validation showed that the optimized the T-shaped fin has a good effect because of better efficiency of heat transfer. Regardless of the configurations, the estimation of internal heat generation is obviously affected by the measurement error. Nevertheless, the measurement of temperature in future time can reduce sensitivity of internal heat generation and root temperature to the measurement error. (C) 2010 Elsevier Ltd. All rights reserved.
This paper presents an implementation of the Jacobi power flow algorithm to be run on a single instruction multiple data (SIMD) unit processor. The purpose is to be able to solve a large number of power flows in paral...
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ISBN:
(纸本)9781424487790
This paper presents an implementation of the Jacobi power flow algorithm to be run on a single instruction multiple data (SIMD) unit processor. The purpose is to be able to solve a large number of power flows in parallel as quickly as possible. This well-known algorithm was modified taking into account the characteristics of the SIMD architecture. The results show a significant speed-up of the algorithm compared to the time required to solve the algorithm in a conventional CPU, even when a more efficient sequential algorithm, such as the Newton-Raphson, is used. The accuracy of the performance has been validated with the results of the IEEE-118 standard network.
Genetic algorithms(GAs) are suitable for parallel computing since population members fitness maybe evaluated in parallel. Most past parallel GA studies have exploited this aspect, besides resorting to different algori...
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ISBN:
(纸本)9781424481262
Genetic algorithms(GAs) are suitable for parallel computing since population members fitness maybe evaluated in parallel. Most past parallel GA studies have exploited this aspect, besides resorting to different algorithms, such as island, single-population master-slave, fine-grained and hybrid models. A GA involves a number of other operations which, if parallelized, may lead to better parallel GA implementation than those currently existing. In this paper, we parallelize binary and real-coded genetic algorithms using CUDA API's with C. Although, objective and constraint violations evaluations are embarassingly parallel, other algorithmic and code optimizations have been proposed and tested. The bottlenecks in a parallel GA implementation are identified and modified suitably. The results are compared with the sequential algorithm on accuracy and clock time for varying problems by studying the effect of a number of parameters, namely: (i) population sizes, (ii) number of threads, (iii) problem sizes, and (iv) problems of differing complexities. Significant speed-ups have been observed over the sequential GA.
The purpose of this study is to determine the heat flux distribution and to estimate the workpiece temperature in creep feed grinding. The sequential algorithm of the inverse heat transfer was used for determining the...
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The purpose of this study is to determine the heat flux distribution and to estimate the workpiece temperature in creep feed grinding. The sequential algorithm of the inverse heat transfer was used for determining the heat flux distribution. The amount of heat flux to the workpiece, the energy partition and the convective heat transfer coefficients both at the front and at the back of the heat flux were determined. Three heat source models using the determined amount of heat flux were applied to estimate the workpiece temperature. The workpiece temperatures estimated by the heat source models were compared with that measured by the embedded thermocouple. The scalene triangle model correlated best with measured and theoretical temperature profiles obtained for creep feed grinding. (c) 2006 Elsevier Ltd. All rights reserved.
Background: Ever since the ground-breaking work of Anfinsen et al. in which a denatured protein was found to refold to its native state, it has been frequently stated by the protein fold prediction community that all ...
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Background: Ever since the ground-breaking work of Anfinsen et al. in which a denatured protein was found to refold to its native state, it has been frequently stated by the protein fold prediction community that all the information required for protein folding lies in the amino acid sequence. Recent in vitro experiments and in silico computational studies, however, have shown that cotranslation may affect the folding pathway of some proteins, especially those of ancient folds. In this paper aspects of cotranslational folding have been incorporated into a protein structure prediction algorithm by adapting the Rosetta program to fold proteins as the nascent chain elongates. This makes it possible to conduct a pairwise comparison of folding accuracy, by comparing folds created sequentially from each end of the protein. Results: A single main result emerged: in 94% of proteins analyzed, following the sense of translation, from N-terminus to C-terminus, produced better predictions than following the reverse sense of translation, from the C-terminus to N-terminus. Two secondary results emerged. First, this superiority of N-terminus to C-terminus folding was more marked for proteins showing stronger evidence of cotranslation and second, an algorithm following the sense of translation produced predictions comparable to, and occasionally better than, Rosetta. Conclusions: There is a directionality effect in protein fold prediction. At present, prediction methods appear to be too noisy to take advantage of this effect;as techniques refine, it may be possible to draw benefit from a sequential approach to protein fold prediction.
An approach in which manually written task procedures are used is proposed for generating natural and comprehensive task plans. However, semantic inconsistencies may occur in manually programmed procedures. In this pa...
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An approach in which manually written task procedures are used is proposed for generating natural and comprehensive task plans. However, semantic inconsistencies may occur in manually programmed procedures. In this paper, we propose a script management system on the basis of action-relation rules that have been generated from patterns mined by the Prefixspan algorithm. Action-relation rules generated in an interactive manner act as a guide for eliminating or modifying task plans. This paper presents the principle and user interface of the management system and the result of implementing the proposed method.
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